In order to provide high-speed multimedia transmission services, it is necessary in a broadband wireless access system to adopt advanced techniques which counteract the frequency-selective fading effects of wireless channels. Many researchers have appreciated the use of Orthogonal Frequency Division Multiplexing (OFDM), which is well known as an excellent approach for alleviating the detrimental effects of frequency selective fading, and which is a preferred physical transmission technique employed in various wireless standards, and is to be standardized and industrialized.
Mobile multimedia broadcast is an important application of the OFDM technique. An OFDM transmission system requires both frequency synchronization and timing synchronization. Timing synchronization further comprises coarse timing synchronization and fine timing synchronization. The coarse timing synchronization searches in received signals to acquire the timing of the transmission of an OFDM signal, and so as to determine the start time instant of an OFDM symbol. OFDM systems are vulnerable to timing errors as they can introduce inter-subcarrier interference by destroying the orthogonality between subcarriers, and finally lead to the performance degradation at the receiver. Existing coarse timing synchronization methods not only require the receiver to make use of a high-precision crystal oscillator but also impose a heavy computational burden on the timing synchronization module.